Tuesday, April 19, 2011

World's Largest Wheel Loader

The L-2350 loader from LeTourneau Inc. holds the Guinness World Record for Biggest Earth Mover. Designed to center-load haul trucks with capacities of up to 400 tons, the L-2350 provides an operating payload of 160,000 pounds, a 24-foot lift height, and an 11.5-foot reach. Asarco's open-pit Ray Mine in Arizona is so rich in copper that water sprayed on its dirt roads to keep down the dust instantly turns green as the ore oxidizes. If you stand at the bottom of the mine, which covers more than 50,000 acres, and look up at its high, tiered walls, you travel back in time to the top shelf, where the first cuts were made a generation ago by men with picks and shovels. Here at the bottom, though, the world's largest wheel loader--the LeTourneau L-2350--gulps 75 tons in a single bite.The L-2350 is a 2300-hp monster: After tearing into the desert dirt a few hundred times, the steel teeth welded to the bottom edge of its bucket shine like silver. The machine's gaping maw is designed to dump rock and ore loosened by explosives into a seemingly endless line of huge trucks that haul it away for processing. Like most wheel loaders, the LeTourneau is articulated in the middle with massive hydraulic rams that pivot the huge hinge with 3400 psi. The Detroit diesel V16 is the size of a Ford F-350. At a governed 5 mph, the L-2350 burns through 1050 gal of fuel in 24 hours. This $7.6 million machine is so freakishly enormous that it was assembled on-site, and when its useful life is over, it will be scrapped on-site too. It will never have left the mine--from cradle to grave. Only veteran operators are allowed to handle the L-2350, and Ruben Rosalez looks the part. Rosalez, who started out working in underground mines and whose burly build, graying ponytail and weathered work clothes would look perfect atop a Harley, jokingly says his greatest qualification for operating the L-2350 is his "depth perception." But seeing him drive the monster using two joysticks--the left one controls the machine's movements, the right controls the bucket--is to see professional expertise become a mechanical ballet. My perch, a small jumpseat next to his chair, gives me a view of the 13-ft-tall, chain-wrapped tires from high above. "The chains aren't for traction," Rosalez says. "The tires just last longer this way." The whole machine is covered with the mine's dust--washing the L-2350 would itself probably yield a couple of pounds of copper. But we're here today to get that L-2350 a little dirtier. "The name of the game is to fill those trucks," Rosalez explains as he settles in and points to the line of dump trucks.With that, the massive torque plunges the bucket's teeth forward, deep into the dirt. After scooping up the load, the LeTourneau rocks back on its haunches, all the while bouncing on squishy sidewalls like a coast guard cutter in constant 20-ft waves. And when Rosalez lines the bucket up to one of the trucks, it seems to exhale as it dumps the load. "I guess I'm used to the motion," Rosalez says, never losing his rhythm as he fills a truck in three scoops, then blows his horn to signal the next one over. "I don't even feel it. In fact, maybe I love it."Source